Robot With Broken Leg Learns To Walk Again

Antoine Cully and fellow researchers at the Sorbonne University in Paris say they’ve developed a technique that allows a damaged robot to learn how to walk again in just a few seconds.

(Robots recover from damage by trial and error)

This robot has 18 motors to power its six legs. Consequently, its gait depends on 36 different parameters that describe things like the amplitude of the movement of each motor, the phase shifts between them, the duty cycle for each joint and so on.

The hexapod also has an on-board computer and a depth camera to estimate its walking speed. Its goal is to walk as fast as possible.

Before the robot is released into the wild, Cully and co calculate a behavioural repertoire of some 13,000 different gaits. However, they do not evaluate them; so the robot does not know how good each one is when a certain kind of damage occurs. Instead, the robot does this after it has become damaged.

So when the leg finally becomes damaged, the robot chooses a gait from the subset that minimises contact with the ground for that leg. It then measures how quickly it can walk using this gait.

It then uses this information to choose another gait, measures the resulting walking speed and feeds this information back into the model. After just a handful of tests, it can then select the best gait.

I think I saw this very idea demonstrated in a science fiction film thirty years ago. In the 1984 movie The Terminator, the Terminator robot's leg is damaged. Is the Terminator helpless? No, of course it determines a workable gait, and continues its inexorable pursuit of Sarah Connor, as seen in the following clip: